curvecpprintkey: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/curvecpprintkey - from package: nacl

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/curvecpprintkey - from package: nacl-tools

You may install the required package with command apt-get install {package}

Error in other languages:
curvecpprintkey: bevel nie gevind nie
curvecpprintkey: comandă negăsită
curvecpprintkey: comando não encontrado
curvecpprintkey: commande introuvable
curvecpprintkey: command not found
curvecpprintkey: käsku ei ole
curvecpprintkey: không tìm thấy lệnh
curvecpprintkey: komanda nerasta
curvecpprintkey: Kommando nicht gefunden.
curvecpprintkey: kommandot finns inte
curvecpprintkey: komut yok
curvecpprintkey: nie znaleziono polecenia
curvecpprintkey: níor aimsíodh an t-ordú
curvecpprintkey: no se encontró la orden
curvecpprintkey: no s'ha trobat l'ordre
curvecpprintkey: opdracht niet gevonden
curvecpprintkey: parancs nem található
curvecpprintkey: perintah tidak ditemukan
curvecpprintkey: príkaz nenájdený
curvecpprintkey: příkaz nenalezen
curvecpprintkey: команда не найдена
curvecpprintkey: командата не е открита
curvecpprintkey: 命令找不到
curvecpprintkey: コマンドが見つかりません